| 摘要 |
<p>PURPOSE: To provide an exhaust emission control device for an internal combustion engine where installation area is small and a surplus load is not applied on an engine. CONSTITUTION: A branch exhaust pipe (11) is situated in parallel to an exhaust pipe (10) of an engine (1). A first occlusion catalyst (12) is situated in the exhaust pipe (10) and a small second NOx occlusion catalyst (13) is situated in the exhaust pipe (10). An exhaust switching valve (15) having an exhaust hole (17a) is situated at a branch part between the exhaust pipe (10) and the branch exhaust pipe (11). A first feed pipe (24) having a first switching valve (25) and a second feed pipe (26) having a second switching valve (27) are opened between the exhaust switching valve (15) and the first NOx occlusion catalyst (12) and between the exhaust switching valve and the second NOx occlusion catalyst (13). Fuel is fed to the first and second feed pipes (24 and 26) from a feed pump (21). A controller (45) is connected to an NOx storage amount grasping means (40), the exhaust switching valve (15), the first switching valve (25), and the second switching value (27).</p> |
